(1) Field of the Invention
This invention relates to a treating solution supply nozzle for supplying a treating solution to semiconductor substrates, glass substrates for liquid crystal displays, glass substrates for photomasks, or substrates for optical disks (hereinafter simply called substrates), a substrate treating apparatus having this nozzle, and a method of manufacturing a treating solution supply nozzle. More particularly, the invention relates to a technique for controlling the temperature of a treating solution in a treating solution supply nozzle held in a sandwiched state.
(2) Description of the Related Art
In a conventional technique for controlling the temperature of a treating solution in a treating solution supply nozzle, a double pipe construction is known in which a temperature control pipe is disposed to surround a treating solution pipe connected to the nozzle. Japanese Unexamined Patent Publication No. 6-291027 (1994) discloses a nozzle that delivers a treating solution from a treating solution pipe under temperature control by constant temperature water in a temperature control pipe.
In view of a treating solution pipe having to be changed because of a fault or the like, Japanese Unexamined Patent Publication No. 7-263326 (1995) discloses a construction in which a temperature control chamber includes a temperature control pipe having a treating solution pipe removably inserted therein, and constant temperature water is circulated through a sealed space formed between the inner wall of the temperature control chamber and the outer wall of the temperature control pipe.
However, such double pipe construction requires the temperature control pipe to have a large diameter, which does not allow the temperature control pipe a large curvature in time of nozzle movement. Thus, a large space is required in the vertical direction which is perpendicular to a substrate under treatment. This poses a problem that the apparatus cannot be made compact in the vertical direction.
To solve this problem, a technique as shown in FIG. 1 has been proposed. According to this technique, a nozzle 102 having a plate-like solution reservoir 101 is pinched between two temperature control plates 103 in a horizontal direction to control the temperature of a treating solution in the nozzle 102. This realizes a compact apparatus.
Each temperature control plate 103 has a Peltier element (not shown) acting as thermoelectric cooling element, and a cooling water circulating member (not shown) for supplying cooling water to remove heat generating from the Peltier element. Each cooling water circulating member includes a cooling water pipe mounted therein for passing cooling water. The cooling water pipe extends outside to be connected to a cooling water feeder disposed outside. Cooling water is circulated from the cooling water feeder through the cooling water circulating member of the temperature control plate 103.
As shown in FIG. 2, the solution reservoir 101 is in the form of meandering pipe 104 to have a large surface area per volume and define a winding treating solution channel. The treating solution is stored in the meandering pipe 104 at least in a quantity to be used in a next delivery cycle. The solution reservoir 101 has a projection 105 formed at the lower end thereof and connected to the meandering pipe 104. A discharge opening 105a is formed at the tip of the projection 105 for delivering the treating solution.
The internal structure of the nozzle 102 will be described in detail by referring to FIGS. 3A through 3D. FIG. 3A is a section of the nozzle 102 taken on line 604-604 of FIG. 2. FIG. 3B is a side view of the nozzle 102. FIG. 3C is a bottom view of the nozzle 102. FIG. 3D is a section of the nozzle 102 taken on line 605-605 of FIG. 3A. In manufacturing the nozzle 102, as shown in FIGS. 3A and 3D, the meandering pipe 104 is formed by bending a tube having a circular cross section, and is covered by a housing 106. Surfaces of the housing 106 that contact the temperature control plates 103 are formed of a heat conducting material (e.g. aluminum, copper, stainless steel or carbon) to ensure a reliable temperature control.
As shown in FIG. 3D, air layers 107 are formed between the meandering piping 104 and housing 106 to act as heat insulation layers that lower the efficiency of heat exchange with the treating solution. It is conceivable to improve the efficiency of heat exchange by filling the air layers 107 with a high heat conductive filler (e.g. metal paste) which is a highly heat conductive material, or by flattening the meandering pipe 104 to diminish the air layers 107. However, such filling or flattening step takes time and trouble. When the nozzle 102 with such a low efficiency of heat exchange is used in substrate treatment, the treating solution set to a desired temperature is not supplied to the substrate. The substrate treatment cannot be performed accurately.